The present invention relates to perparing articles of fat-based confectionery material, including chocolate, by forming a fat-based confectionery material, including chocolate, into a desired shape.
One method of forming chocolate into a desired shape is by moulding. Moulding of chocolate is normally carried out in the liquid state by casting, i.e. pouring the molten chocolate into a mould followed by cooling. The moulded chocolate is usually demoulded quite easily after cooling, due to the thermal contraction of the chocolate as it sets, giving a product with an attractive glossy surface. However, the disadvantages of conventional chocolate moulding are the requirement for cooling tunnels which consume space and time, the product cannot be wrapped directly because of the cooling step and it is not possible to achieve exact weight control. The formation of the chocolate centres for SMARTIES candy, currently involves the use of rollers which also require a very high cooling capacity.
European Patent Application Publication No. 0 603 467, which sets forth the contents of Application No. 93114251.7, (herein "the '467 Application") describes a process for plastically extruding a fat-containing confectionery material which comprises feeding the fat containing confectionery material into an extrusion device and applying pressure to the fat-containing confectionery material in a substantially solid or semi-solid non-pourable form upstream of a flow constriction whereby the temperature, pressure, contraction ratio and extrusion rate are such that the fat-containing confectionery material is extruded substantially isothermally and remains in a substantially solid or semi-solid non-pourable form to produce an axially homogeneous extruded product and which has a temporary flexibility or plasticity enabling it to be physically manipulated, cut or plastically deformed, e.g. it can be bent, twisted or forced into a mould. The '467 Application also describes an injection moulding process wherein the temporarily flexible extruded product is injection moulded under pressure at a temperature below the normal melting point of chocolate. This injection moulding process is substantially isothermal and subsequent cooling is therefore unnecessary so that the product is suitable for demoulding immediately after the injection moulding is complete. However, because a subsequent cooling is not necessary, thermal contraction does not necessarily occur and, in some circumstances, demoulding and obtaining a high quality surface finish may be difficult to achieve.